Experimental study on optimized using activated agricultural wastes at hemispherical solar still for different types of water

The subsequent work aims to improve freshwater production and reduce the cost of generated water with little energy expenditure. Thermo-economic performance, hourly and daily production were evaluated by the experimental study on a hemispherical solar still in several configurations. The two floating agricultural waste materials utilized in the experiment were charcoal derived from guava tree wood (CHL) and carbonized corncobs (CCC). To enhance photothermal properties of the utilized primary materials, both have undergone physical and chemical activation by HCL or NaOH under specific conditions. In addition, the experiment was conducted using both seawater and lake water. Each modified distiller's performance was compared to that of a conventional unit in terms of thermal efficiency, exergy efficiency, daily output, and cost of freshwater in the climate of Kafrelsheikh, Egypt (31.09679°N, 30.94945°E) from 9:00 A.M. to 5:00 P.M. Therefore, this study aims to enhance the photothermal properties of charcoal and corn cobs by chemical and physical activation, which lead to enhance the efficiency of the hemispherical solar still by using this modified agricultural waste in its base compared to the traditional way. The daily productivity, thermal, and exergy efficiencies for H.CCC.LW were 4455 mL/m2,41.19%, and 3.85% showing improvement compared to a conventional hemispherical solar still by 41.2%, 40.72%, and 59.09%, respectively. At approximately 0.014 $/L (a savings of 26.70%), H.CCC.LW was shown to be the most cost-effective source of freshwater.